Combined drill and countersink.



W. H. SEMON. COMBINED DRILL AND GOUNTBRSINK. APPLICATION FILED MAY 11, 1911.

. Patented Sept. 22, 1914 WILLIAM H. snmon, or cnnvnnnma, 01110.

COMBINED mum. Aim cotm'rnnsmio To all whom z'tmay concern Be it known that, 1, WILLIAM a citizen of the-United States, resident of Cleveland, county of. Cuyahoga, and, State of Ohio, have invented anew and useful SEMON,

Improvement in Combined Drills and C0un- 'tersi'nks,

of which the following is a specification, the principle of the invention being hereinexpl'ained andthe 'e's't mode in which I have contemplated ap lying that principle, so. as to distinguish vcntions.

. My invention and countersink,

relates to a combined drill and more particularly to a specialized improvement associated with the different parts ofthe latter.

The ob ect is .to' provide a countersink drill for usein connection with standard twist drills which while fulfilling the demands alike for simplicity and economy of construction will nevertheless prove, more efficient. v

The: said invention which are hereinafter fully described and particularly set forth in the claims,

The annexed drawings and the following description set forth in detail certain means embodying my invention, the disclosed means, however, constituting but one of various mechanical forms in which the principle of my invention may be applied.

In said annexed drawings Figure 1 represents a combined drill and countersink of the simplest form embodying my invention. Fig. 2 is a section on line II-II of Fig. 1, looking in the direction of the arrows. Fig. 3 represents an adjustable form 'of drill and countersink in accordance with the principle of the invention. Fig. 4 is a detail ,view of parts thereof in different relative positions. Fig. 5 is a section on line V of Fig. 3 looking in the direction of the arrows. Fig. 6 is a section on line VI-VI of Fig. 3, looking in the direction of the arrows.

Referring first to Fig. 1, in which a twist drill A is shown surrounded by one form of my improved countersink drill: This lat- B, comprises a cylindrical shank porprovided with a cylindrical opening corresponding precisely 1n size to the diameter of the drill A. which it is adapted to receive. A set-screw b is provided for the purpose of fixing the'drill and-socket to each other. The lower portion -of the countersink B is provided with one or from other inconsists of means Specification of Letters Patent. V Patented Sept, 22, 1914 Application filedlfayll, 1911. Serial No. 626,635.

\ .more cutting members proper I)", each of. which, in accordance with the inyent1on, 1s provlded with an inwardly curved -.1ns1de edge I), the extremity of which forms an inwardly twisted lip 6 conv forming exactly, and 7 preferably immediately adjacent or actually contiguous, to the central or bottom portion of the grooves as seen in Fig. 6. This positively insures the inside or actual cutting edges ofthe countersink being inside the diameter of the hole which is being drilled by the primary 1 drill, and hence necessarily inside the diameter of the hole in the shank bf of the countersink. Moreover, this inner edge of each of the cutting members should have the same degree of twist' as the fluting of the primary drill with which it isadapted to be used.' The inner edge may also follow the groove of the primary drill for the greatest distance that is practicable, in order that the countersink as a whole may have its cutting edge considerably worn down by grinding without precluding the continued usage thereof.

Asshown in the drawing the general cross section of each connecting member is triangular. This leaves a space bounded by the connecting member andby the surface of the'flute which permits the shavings to pass upwardly and be guided away from the said members b In the adjustable form shown in Figs. 3 to 6 inclusive, the shank of the countersink drill is divided into two separable parts B and B The inner faces of these divisions of the shank, or those surfaces which 'actuallycngage the surface of the primary drill are V-shaped, in order to insure proper centering and alinement of the drill and countersink with respect to each other. An adjusting band C surrounds the divisions of theshank B and B and is provided adjacent the division B with a screw-threaded opening 0.

A set-screw D is adapted to screw-thread through this opening 0, and on its inner ex tremity has a swivel end d loosely mounted in themember B -Through the opposite side of the band C and specifically through the correspondingly screw-threaded opening 6 a set-screw E is adapted to extend for the purpose of fixing the member B and its attached cutting member b Accordingly, as will be manifest, the manipulation of the set-screw D will serve to clamp the two divisions B and B of the shank about the shank of the drill A, and hence compose an adjustable shank for countersink drills, as.

willbe eail nderstood. Mither one or alIof e possible divisions of the shank inthis adjustable form may be provided with sucha cutting member 6 having an edge 6 and cuttinglip, b. v This edge is likewise designedso that it fits into and follows for any chosen distance one of the grooves of the primary drill. Since, after the manner of its conjunctive use as previously explained in connection with Fig. '1, the inside edge of the countersink cutting member fits into and conforms 1n curvature with the groove of the primary drill, a clean cut 1s absolutely guar-, anteed the instant thiscutting lip of the countersinkfcomes in contact with the edge of the hole, already drilled by the primary drill. Furthermore, since the inside edge of this cutting member fits into and follows for any desired distance a groove onthe primary drill, the countersink may be sharp ened again and again after the edge on the lip has worn down, before impairing any. of the originally. intended functions, and then by reason of its being removably associted with the shank may be readily replaced, when this finally becomes necessary.

As shown in the drawings the lower or. cutting portion of the members If is of like cross-section throughout so that as the drill is shortened by sharpening, the conformation of the lower end 1s not changed-and the successive cutting edges formed by such relative to the axis of the drill.

.Having fully described my invention, what I claim and desire to sgsnre by'lettvs Patent. is:

1. A comllined dfill and countersink comprising/the combination with a drill having & fiute; of a countersink-member secure thereto and rovided with a transverse cutting edge; t'e inner longitudinal portion of said member lying within and corre spondin in curvature with the curvature of said %ute; said countersink-member having its cutting "end constructed so as to have a material portion of the length thereof of like cross-sectional area throughout, successivecross-sections having a similar relatlon to the axis of the drill. 1

2. In combination, a drill and an outer countersink-member having two converging inner surfaces ending substantially in a line conforming in curvature with 'andfextending into the flute of the drill; the said countersink-member furthermore being formed with a cutting edge with its extremity extending transversely with respect to said inner curved line and joining the lower extremity thereof. 7 I

Signed by me, this 9th day of May, 1911.

. i W. H. .SEMON.

Attested by OURT B. MUELLER,

WINFRED WALTZ.

sharpening always occupy the same position 

